X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/f172cb8200f08ba1c6735a0d507991c877c0d68f..3c5f62640d5072b3ab9116a3852294ab58ebbfbb:/src/common/imagjpeg.cpp

diff --git a/src/common/imagjpeg.cpp b/src/common/imagjpeg.cpp
index f279fed885..2a24dce990 100644
--- a/src/common/imagjpeg.cpp
+++ b/src/common/imagjpeg.cpp
@@ -17,6 +17,7 @@
 #if wxUSE_IMAGE && wxUSE_LIBJPEG
 
 #include "wx/imagjpeg.h"
+#include "wx/versioninfo.h"
 
 #ifndef WX_PRECOMP
     #include "wx/log.h"
@@ -28,7 +29,7 @@
 
 // A hack based on one from tif_jpeg.c to overcome the problem on Windows
 // of rpcndr.h defining boolean with a different type to the jpeg headers.
-// 
+//
 // This hack is only necessary for an external jpeg library, the builtin one
 // usually used on Windows doesn't use the type boolean, so always works.
 //
@@ -148,14 +149,11 @@ CPP_METHODDEF(void) wx_term_source ( j_decompress_ptr cinfo )
 
 // JPEG error manager:
 
-struct wx_error_mgr {
-  struct jpeg_error_mgr pub;    /* "public" fields */
-
+struct wx_error_mgr : public jpeg_error_mgr
+{
   jmp_buf setjmp_buffer;    /* for return to caller */
 };
 
-typedef struct wx_error_mgr * wx_error_ptr;
-
 /*
  * Here's the routine that will replace the standard error_exit method:
  */
@@ -163,14 +161,14 @@ typedef struct wx_error_mgr * wx_error_ptr;
 CPP_METHODDEF(void) wx_error_exit (j_common_ptr cinfo)
 {
   /* cinfo->err really points to a wx_error_mgr struct, so coerce pointer */
-  wx_error_ptr myerr = (wx_error_ptr) cinfo->err;
+  wx_error_mgr * const jerr = (wx_error_mgr *) cinfo->err;
 
   /* Always display the message. */
   /* We could postpone this until after returning, if we chose. */
   (*cinfo->err->output_message) (cinfo);
 
   /* Return control to the setjmp point */
-  longjmp(myerr->setjmp_buffer, 1);
+  longjmp(jerr->setjmp_buffer, 1);
 }
 
 /*
@@ -231,13 +229,19 @@ static inline void wx_cmyk_to_rgb(unsigned char* rgb, const unsigned char* cmyk)
 
 bool wxJPEGHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose, int WXUNUSED(index) )
 {
+    wxCHECK_MSG( image, false, "NULL image pointer" );
+
     struct jpeg_decompress_struct cinfo;
-    struct wx_error_mgr jerr;
+    wx_error_mgr jerr;
     unsigned char *ptr;
 
+    // save this before calling Destroy()
+    const unsigned maxWidth = image->GetOptionInt(wxIMAGE_OPTION_MAX_WIDTH),
+                   maxHeight = image->GetOptionInt(wxIMAGE_OPTION_MAX_HEIGHT);
     image->Destroy();
-    cinfo.err = jpeg_std_error( &jerr.pub );
-    jerr.pub.error_exit = wx_error_exit;
+
+    cinfo.err = jpeg_std_error( &jerr );
+    jerr.error_exit = wx_error_exit;
 
     if (!verbose)
         cinfo.err->output_message = wx_ignore_message;
@@ -248,10 +252,12 @@ bool wxJPEGHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbos
        * We need to clean up the JPEG object, close the input file, and return.
        */
       if (verbose)
+      {
         wxLogError(_("JPEG: Couldn't load - file is probably corrupted."));
+      }
       (cinfo.src->term_source)(&cinfo);
       jpeg_destroy_decompress(&cinfo);
-      if (image->Ok()) image->Destroy();
+      if (image->IsOk()) image->Destroy();
       return false;
     }
 
@@ -271,10 +277,21 @@ bool wxJPEGHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbos
         bytesPerPixel = 3;
     }
 
+    // scale the picture to fit in the specified max size if necessary
+    if ( maxWidth > 0 || maxHeight > 0 )
+    {
+        unsigned& scale = cinfo.scale_denom;
+        while ( (maxWidth && (cinfo.image_width / scale > maxWidth)) ||
+                    (maxHeight && (cinfo.image_height / scale > maxHeight)) )
+        {
+            scale *= 2;
+        }
+    }
+
     jpeg_start_decompress( &cinfo );
 
-    image->Create( cinfo.image_width, cinfo.image_height );
-    if (!image->Ok()) {
+    image->Create( cinfo.output_width, cinfo.output_height );
+    if (!image->IsOk()) {
         jpeg_finish_decompress( &cinfo );
         jpeg_destroy_decompress( &cinfo );
         return false;
@@ -389,13 +406,13 @@ GLOBAL(void) wx_jpeg_io_dest (j_compress_ptr cinfo, wxOutputStream& outfile)
 bool wxJPEGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbose )
 {
     struct jpeg_compress_struct cinfo;
-    struct wx_error_mgr jerr;
+    wx_error_mgr jerr;
     JSAMPROW row_pointer[1];    /* pointer to JSAMPLE row[s] */
     JSAMPLE *image_buffer;
     int stride;                /* physical row width in image buffer */
 
-    cinfo.err = jpeg_std_error(&jerr.pub);
-    jerr.pub.error_exit = wx_error_exit;
+    cinfo.err = jpeg_std_error(&jerr);
+    jerr.error_exit = wx_error_exit;
 
     if (!verbose)
         cinfo.err->output_message = wx_ignore_message;
@@ -407,7 +424,9 @@ bool wxJPEGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbo
          * We need to clean up the JPEG object, close the input file, and return.
          */
          if (verbose)
+         {
             wxLogError(_("JPEG: Couldn't save image."));
+         }
          jpeg_destroy_compress(&cinfo);
          return false;
     }
@@ -465,7 +484,7 @@ bool wxJPEGHandler::DoCanRead( wxInputStream& stream )
 {
     unsigned char hdr[2];
 
-    if ( !stream.Read(hdr, WXSIZEOF(hdr)) )
+    if ( !stream.Read(hdr, WXSIZEOF(hdr)) )     // it's ok to modify the stream position here
         return false;
 
     return hdr[0] == 0xFF && hdr[1] == 0xD8;
@@ -473,4 +492,9 @@ bool wxJPEGHandler::DoCanRead( wxInputStream& stream )
 
 #endif   // wxUSE_STREAMS
 
+/*static*/ wxVersionInfo wxJPEGHandler::GetLibraryVersionInfo()
+{
+    return wxVersionInfo("libjpeg", JPEG_LIB_VERSION/10, JPEG_LIB_VERSION%10);
+}
+
 #endif   // wxUSE_LIBJPEG